The 8V series of engines (and the 6V) were the mainstays in motorcoaches, seated and otherwise) forever. They were durable simple engines, but like anything mechanical they can fail. Cooling on the two stroke engines is a primary consideration. I think they are prone to plug radiators and routine coolant maintenance is mandatory.
That is not to say the series 60 is bullet proof. There was a period of time when the S60 was having piston failures that were catastrophic.
My old 8V92 eventually needed a recoring in the radiator when it was about 10 years old and I had a crack in one head between two of the valves that was allowing coolant into the air box. But it had 250,000 miles on it at the time. The crack should not have happened, but it did. I had it rebuilt at that time, but the condition of the engine apart from the crack indicated that engine would have easily gone 500,000 miles plus.
The Beaver that Colorado bus is buying is pristine. It shows care far beyond what would be described as normal, and shows continued and constant attention to detail. I would not hesitate to buy that coach. I did recommend that Jim and Chris get it to a Detroit / Allison dealer to see if they can do an in depth analysis of the engine and transmission history because the engine did have a number of codes in its history.
